Many conventional motor vehicles include engine controls and vacuum motors that are operated by a vacuum pressure supplied by an internal combustion engine. After cold-starting the engine, there is not adequate vacuum pressure to operate these devices. In these situations, especially with a diesel engine that has no vacuum source, there is typically a need to operate a vacuum pump for a short period. Ideally, the vacuum pump would be selectively coupled to the engine, such that insufficient vacuum pressure would couple the engine output to the vacuum pump and sufficient vacuum pressure would uncouple the engine output from the vacuum pump. Although this need could be filled by conventional pressure actuated clutch pulleys, these clutch pulleys are designed to transfer a larger amount of torque and are typically designed with splines or keys, which burden the clutch pulley with unnecessary weight and expense. Thus, there is a need in the art of motor vehicles, if not other arts, for a pressure actuated clutch pulley that is lighter and cheaper than the conventional clutch pulleys.